Electrical control device



Oct. 11, 1932. v. G. LEACH ELECTRICAL CONTROL DEVICE Filed Nov. 26. 1930wm E d ww Q N w m 5M UN-ITED. s TAEs PATENT oFl-l VERNON G; LEAGH,CHICAGO, ILLDTOIS, ASSIGNOB, T MODERN COAL BURNER 'IANY, OF CHICAQgQ,ILLINOQIIS, A CORPORATION 0F ILLINOIS nfncrnrcnr. coNTnoL nnvrcaApplication :tiled Noyember, 1930. Serial No. 488,806.

This invention relates to an electrical control device and moreparticularly to such a .device which can be carefully adjusted toregulate the time of current iiow through one plurality of independentelectric circuits. g

Many types of control devices have been proposed in the past but for themost part these devices fail to provide proper current control or are sointricate as to be diliicult to operate, construct or repair. l Y I havenow constructed an electrical control device which is simple inconstruction and is susceptible of accurate and careful adjustment toproperly control the intermittent iiow of current through one or aplurality of independent electric circuits. It is accordingly an objectof this invention to provide a'currentcontrol device for elec; triccircuits which is capable of adjustment for regulatin the flow ofcurrent. intermit-l tently throug a plurality of independent circuits.'

It is a further important object of this invention to provide a currentcontrol device which is relatively simple in construction, has but asmall initial and upkeep cost, and

- is highly eiiicient in operation.

It is an importantV object of myinvention to provide simple mechanicalmeans for actuating electric switches to alternately interrupt and closeelectric circuits for predetermined periodsof time. .It is also animpor'- tant object of my invention to provide means for carryingput the.above-mentioned object,

which means comprise a rotatable drum so shaped that it. provides, ineffect, a great number of cam shaped rings to be selectively engaged bya switch-actuating finger so that electric circuits may be opened orclosed 'for predetermined periods of time, and so that ,means for.lmechanically actuating a plurality of switch-contrlling'fingers to openand..

these periods may be readily increased or,-

diminished in exceedingly small steps.

It is also'a further and important obJect of my invention to provideinexpensive close electric l'circuits' for redetermined periods of time,which peri'o s ma be increased or'ldiminished in exoeedmg y small steps,and to provide'means for regulating the length of the periods duringwhich the circuit 1s open or closed of such simplici as to be capable ofmanual control by ordlnary workmen, or of automatic control.

Other and further important ob'jects of this invention will becomeapparent from the following descriptiony and appended claims. w'

Referring to the drawing which discloses a preferred embodiment of myinvention:

Figure 1 is a top plan view of the' control d vice of this invention.

1igure 2 is a side elevational view ofy said control device.

On the drawing:

The control device of this invention, indicated as a whole by thereference numeral 1,

comprises a rotatable cam drum 2 mounted on a shaft 3 which isjournalled at its ends 4 in the hubs 5 of spiders 6. A supporting base 7is secured to, or formed inte al with, said spiders 6 and .is providedwith means (not shown) for securing the control device 'to-a suitablesupport, such as the wall 40 of a box or cabinet 41. l

The rotatable drum 2, as shown, has a sub stantial portion of itsperiphery cut away to provide a cam surface 8l`-for a purpose to belater explained. Preferably, the cut-away portion of the roll peripheryis such that the edge 10 dening said cut-away portion is substantiallyin the form of a helix, the form of the edge, however, being such as toobtain the desired characteristics in the particular installation Ainwhich my device is to be used. The drum 2 may be considered in effect tobe 'composed of a great number of ,thin cams,

mounted side b side, with their active sur faces so shape and vwith thecams so positioned in relation to eachother, as to present a'helix whenthe drum seen from above and at a certain point in a revolution.A Whenthe drum is viewed from above at another p oint in the revolution of thedrum. a straight A Said shafts 13 'and 14 are operatively connectedtogether by means of aclutch member 16 secured to shaft 13 4and a clutchmember 17 secured to the shaft 14. The motor 15 is lmounted as a part ofthe control device on the su porting base 7-.

A. p urality of hollow bars or rods 18 are journalledin the bearings 19on the ends of the radial arms 20 of spiders 6 so as to lie arallel tothe major axis of said drum 2 ad- ]acent the periphery of the same. Eachof said bars or rods 18 has a slot 2l therein extending substantiallythe full length of said rods 18. A ring 22 carrying a shoe 23, adaptedto bear against the periphery of the drum 2 is slidably mounted on eachrod 18.

Each ring 22 is slidably adjusted on the rod 18 by means of a plungerrod 24 which extends into the hollow rod 18, and the ring 22'- issecuredto the rod 24 by means of a set screw 25. The shanks of said setscrew 25 are located in the slots 21 in said hollow rods 18- to therebyprevent relative rotation between said rings 22 and said rods-18.

Toretain the rod 24 in adjusted position in the'hollow rod 18 a collar35 is'suitably mounted on an end of the rod 18 and is provided with anapertured resilient clip or clutch member 26, suitably secured at oneend thereof on the collar 35 to normally grip the v-rod 24. The collar35 is provided with a {inger-rest V26a so that the rod 24 may bereleased or movement by the operator by pressing the clip 26 towards thefinger-rest 26a and against a coiled spring 27a, positioned between'thefinger-rest 26a and the clip 26 to normally urge the clip intoengagement with the rod 24. l

A plurality of collars 27 are rigidly secured to the opposite ends ofsaid hollow rods 18, each collar having thereon lone or moreconventional tiltable mercury' switches 28.'V

plnir of conductors 29 Each switch 28 has a joined thereto, all of w chlead to a control board 30 secured to said supporting base 7. Saidcontrol board is provided with a pairof terminals 31 for each switchwhereby the switch may be connected in an electric circuit (not shown).v Y

The device, including the switchboard, is preferably enclosedl in thedust-proof and weather-proof casing 41 with nothing extending ontsidethe casing but the conduits for 'the rods connected Y means sothat thecarrying the wires to the switchboard, and

thecollarsandtherods`24.

Sincetherods24requireno1noretliana straight-line pushA or pull toyeffect movement of the shoes 23, it will be obvious'thatV theV clampingmember 26 may eliminated and to some ysuitable driving be 'so positionedwithrespe -vide a further con position ofthe shoe, and.`

' the operation ofthe attached switches, may

` Y be governed by some remotely positioned defor instance, the gauge ofa boiler. The rods may attachedby simple means to the float of a. watertank or sump to govern the operation of pump motors.

With this arrangement itwill be appreciated that the opening and closingof the switches 28 will depend upon their relative positions asdetermined by whether the shoes 23 are in or out of contact with the camsurface 8. The rods 18 are given a constant tendency to rotate so as topress the shoes 23 into contact with the cam surface 8 by providingcounter-weighting means 32 on said collars 27. Said counter-weightingmeans 32 also cause the rods, when the shoes are out of -'contact withthe cam surface, to move to a position in which the switches 28 will beopen', thereby breaking the associated circuits. Movement of the rods isprevented and the switches are retained in closed position when theshoes 23 bear against the cam surface 8 of the drum 2. In other words,when a shoe or brush 23 is in contact with the cam surface 8, the hollowrods 18v will be held against rotation, the eliect of thecounterweighting means being merely to force said shoes into closecontact with said surface. However, when theshoes reach va cut-awayportion ofthe drum surface during the rotation of said drum 2, thecounterweighting means will rotate said rods 18 to tilt said switches 32and open the circuit.

The rods 18 are prevented from rotating beyond the point required toopen the switches l 32 by means of cooperating stop members on said rodsand a spider 6, which comiprise studs 33 projecting inwardly from one ofsaid spiders and winged sleeves 34 rigidly secured to said rods andadapted to strike said studs when the mercury switches have been tilteda dista-nce suilicient` to open the same.

A The solid periphery of the drum 2 is as stated above in the form of acam surface and accordingly it is possible to vary the period eachswitch is retained in open or closed position by sliding the shoes 23along the rods 18 to-provide contact between the said shoes and drumperiphery for the period of time desired. It will be obvious that a shoe23 may ct to either end of the drum 2, and the ends of the drum so sped, that the attached switch4 28 may the associated circuit in open orclosed position during continued revolution of. the drum. Furthermore,the speed of rotation of the drum may be regulated -to pro- 1 of thistime period. The operation'of device is'a's follows:Apairote'minaJsBlonthe board 30is connected in an electric circuitincluding a @sa 1e-aa a han i 18 e SW1 .1S en a 0 said` l ng Amo 18tobearonthesurfeeofthedrum 2Q The motor 15 is then started and the drum2 caused to rotate. -As'the drum rotates, the I a'deinite pathway on theperiphery of the drum and, while in contact with the cam surface"8 ofthe drum, maintains the switch' in operative position to keep its.associated circuit interrupted or closed, as decomprising a rotatabledrum having a porsired. However, when saidV shoe 23 strikes a 'cut-outportion, the rod 18 carrying the same will be rotated by means of theassociated counter-weighting means 32 thereby tilting its associatedmercury switch effecting an opening of said electric circuit. The switch32 remains in its tilted position during further rotation of thedrumuntil af portion of the cam surface lof said drum again comes intocontact with the shoe 23, whereupon the rod 18 will be swung inadirection to bring the mercury switch backto its original position andagain close the circuit. If, at any time, it is desired to vary theperiod whic the circuit is maintained open 'or closed it is onlynecessary to-operate the plunger arm 24 to position the shoe 23 at theproper point on the cam surface 8.

For simplicity I have disclosed the operation of -my devicevwith onlyone electric cir- -cuit but Vit will beunderstood that each mercuryswitch is to'f'be connected in a circuit wherebyA independent-control ofa plurality of circuits may beobtained at the same time.

It will also be evident that a plurality of switches may be connectedwhere one is now shown to control a lurality-of devices, vor else to beconnected) in parallel to handle heavy currents.

I also contemplate the application of the drum in situations where, withproper attention paid to the insulating of affected parts, the drumitself may be one conducting element in an electric circuit withtheshoes acting as the other conducting or switch elements.

While I have disclosed the preferred embodiment of my invention, it willbe undevstood that I do not ropose to be limited thereto as variousmodifications in the structure disclosed may be made without departingfrom the spirit of my invention.

' I claim as my invention:

1. A control device for an electric circuit tion of its periphery cutaway to define a solid cam surface, oscillatable means adjacent said camsurface, a shoe carried by said oscillatablemeans and adapted to bearagainst the -cam surface 'in one position of rotation of said drum andproject into said cut out por- `tion in another position of rotationvofsaid drum, means for adjusting said shoe on said oscillatable meansAsothat said shoe may be traversed by different paths around said p e.--

riphery, a tiltable mercury switch on said osclllatable means andweighted means on said oscillatable means for oscillatingsaid oscil- -hlatable means when said shoe moves into a cut-out portion of said drumsurface to tric circuits comprising a rotatable drum havin a portion'of.its periphery cut away to de ne a solid cam surface, a plurality ofoscillatable means adjacent said cam surface, shoes carried by saidoscillatable means adapted to bear against said cam surface in oneposition of movement of said drum and project into the cut out portionof said drum periphery in another position of movement of said' drum,mercury switches on said oscillatable means in closed condition whensaid shoes contact said cam surface, means for adjusting said shoes onsaidviosc'illatable means so that said shoes may be traversed bydifferent pathsl around the periphery of said drum, means for retainingsaid shoes in adjusted position, means for connecting said vswitches indifferent electrics/ circuits and means for osciltinuity of current flowthrough a plurality of independent electric circuits, comprising arotatable drum having a portion of its periphery cut away substantiallyalong a helical curve to provide a solid cam surface, a

plurality of loscillatable arms adjacent said cam surface, a shoecarried by each oscillatable arm and adapted to bear against said camsurfaces or project into a cut-out portion of said drum periphery atdifferent periodsv of rotation of said drum, independent means v forsliding each shoe alon an oscillatable arm to vary the pathway to etraversed by the different shoes around the drum periphery, a

tiltable mercury switch on each arm in closed position whenpsaid shoescontact said cam surface, and means on each 'arm -for independentlyoscillating an arm when theshoe thereon strikes a cut out portion ofsaid drum periphery tov tilt the switch on said arm and thereby open thecircuit containing said' switch.

4. A control device for a plurality of independent electric circuits,comprising a'rotatable drum" having a portion of its surface cut awayalong a helical curveto provide the l periphery'of said drumwith a camsurface,

a plural1t of hollow arms journalled adjacent sai drum periphery, a shoeslidably mounted on each arm adapted to contact said cam surface in onepositionv of rotation of said drum and project into said cut out portionin another position of rotation of said drum-,l aftiltable mercuryswitch' ri d with each arm, means for connecting eac switch in anindependent circuit, plungers in said l ollow arm secured to said shoesfor varying the position of said shoes on said hollow ajrms and therebythe path to be traversed by 'saidtilt said mercury switch and open shoesaround said drum periphery,1neans for retaining said shoes in ad]ustedposltlon and means on each hollow arm for oscillating lsaid arm when theshoe on said arm reaches *s a cutout portion of said drum periphery tothereby tilt the switch on said arm and open thecircuit containing saidswitch. A

' g 5. A'devce asvspecied in claim 4 including a spring'- clip forretaining each plunger.

n arm and the shoe secured thereto in adjusted `position.

` 6. A device as in claim 4 wherein each hol- -low arm has a slot andthe plunger arm is connected to the shoe on said hollow arm hy* .115 ulvscrew having its shank positioned in said s ot. Y In testimony whereof Ihave hereuntosubv scribed my name at Chicago, Cook County,- Illinois.

' j 4 '1- VVERNON. e. 'LEACH fak

